[media] v4l2-subdev: use MEDIA_ENT_T_UNKNOWN for new subdevs

Instead of abusing MEDIA_ENT_T_V4L2_SUBDEV, initialize
new subdev entities as MEDIA_ENT_T_UNKNOWN.
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/media-device.c

@@ -435,6 +435,12 @@ int __must_check media_device_register_entity(struct media_device *mdev,
 {
 	int i;
 
+	if (entity->type == MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN ||
+	    entity->type == MEDIA_ENT_T_UNKNOWN)
+		dev_warn(mdev->dev,
+			 "Entity type for entity %s was not initialized!\n",
+			 entity->name);
+
 	/* Warn if we apparently re-register an entity */
 	WARN_ON(entity->graph_obj.mdev != NULL);
 	entity->graph_obj.mdev = mdev;

drivers/media/v4l2-core/v4l2-subdev.c

@@ -584,7 +584,7 @@ void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops)
 	sd->host_priv = NULL;
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	sd->entity.name = sd->name;
-	sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV;
+	sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN;
 #endif
 }
 EXPORT_SYMBOL(v4l2_subdev_init);

include/uapi/linux/media.h

@@ -42,6 +42,14 @@ struct media_device_info {
 
 #define MEDIA_ENT_ID_FLAG_NEXT		(1 << 31)
 
+/* Used values for media_entity_desc::type */
+
+/*
+ * Initial value to be used when a new entity is created
+ * Drivers should change it to something useful
+ */
+#define MEDIA_ENT_T_UNKNOWN	0x00000000
+
 /*
  * Base numbers for entity types
  *
@@ -76,6 +84,12 @@ struct media_device_info {
 
 /* V4L2 Sub-device entities */
 
+/*
+ * Subdevs are initialized with MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN,
+ * in order to preserve backward compatibility.
+ * Drivers should change to the proper subdev type before
+ * registering the entity.
+ */
 #define MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN	MEDIA_ENT_T_V4L2_SUBDEV_BASE
 
 #define MEDIA_ENT_T_V4L2_SUBDEV_SENSOR	(MEDIA_ENT_T_V4L2_SUBDEV_BASE + 1)